The term gay has changed in meaning over the last 50 years. The Flintstones opening sequence uses the phrase "we'll have a gay old time" which obviously doesn't fit the modern definition. Do people still commonly consider the phrase "a gay old time" as equivalent to an enjoyable time?

Even wiktionary[1] considers it a dated phrase.

[1] https://en.wiktionary.org/wiki/gay_old_time